Telephone system



H. l. CLAUSEN.

i TELEPHONE SYSTEM.

APPLICATION FILED IAII.4. 191s.

Famed (IGI. `III,I92II vnecter brushes 33, 34, 35 in a Well-known' manner. l/lheny the brushes are set on the terminals 32, 31, 30 of the line sub 1 a circuitisclosed from ground supplied by the connector circuit, brush 35, terminal 30, inner Aarmature vand back contact of relay 15 through the right-hand Winding of magnet 13 to battery. The right hand `Winding of magnet 13 is so designedas to operate the left-hand armatures, but not to operate the plunger 12. The operation of magnetf13 cuts olf thefline relay 14 and places a busy test condition on the multiple jacks? and 8 as described above.

' Assume now that the automatic subscriber at sub 1 calls the manuel line at subY 5. His Icall is extended 'to the connector brushes 36, 37, 38 which arestepped onto the terminals 39, 40, 41frespectively of the line sub v5. A :cirmiit is then-closedk from ground through a resistance in thejconn'ector circuit to brush l 38, terminal 41, the inner armature and back contact of relay 16, lConductor 46, through the Winding of vrelay 17 Ato battery. The operation of relay 117 closes a .circuit I Jfrom battery'V through the Winding or relay 17, throughy thelet-hand armature and front Contact of relay 17, to the test'termin'als of multiple jacks 10 and 11, causing the line to test. busy at the operators switchboard.

' From this point-the call is completed and connections restored to normal in a Wellknown manner.,v 7 n e In the three cases assumed above, We have traced calls originated at anautomatic station andY noted that during the establishment of 'such connections and during conversation "magnet 13l is operated. It at such times an` operator should attempt to call or to listen in on a line sub 1 by plugging in over the busy test condition on jack 7 or 8,. it is obvious that no talking or listening connection Will be afforded, since neither relay 15 ofan automatic line, or relay 16 of a manual line can be operated.

lAssume that the manual subscriber at sub' 3V desires 'a connection With the Vautoi matic line atsubL 1. The connection is eX- VVVtended rto the operators cord circut 6 in a `Ymannerto be described. later. The operator vso then tests'themultiple jack 7 or 8 of the flinefin the usual manner, vand nding it free,

she inserts theplug 9 of `her calling cord 6. When the plug'9 in inserted in jack 7 or 8 a circuit is closed from battery through the lampy 50,A resistance 51, sleeveV of plug 9.,

y sleeve of'jack 7 or 8, conductor 21, outer left-hand armature and back contact of mage 5V net 13, through the Winding of relay 15 to ground. The operation of relay 15 closes at its inner armature and front contact, a circuit from ground to terminal 30, to hold the line 'of sub 1 busy, and at its middle and outer armatures and front contacts, it

Assume now' that the manual subscriber at sub`3 calls the manual subscriber at sub The call is extended to the operators cord in a manner to be described later, she tests the line sub 5 by touching the tip of her plug 9 to the sleeve of jack 10 or 11, and i.

inding the line idle inserts the plug 9 in the jack 10 or 11. A circuit is then closed from battery through lamp 50, resistance 51, sleeve of plug 9 and jack 1() or 11, the lefthand armature and back contact of relay 17, conductor 47 through the Winding of `relay 16 to ground. The operation of relay 16 closes at its inner armature and front contact, a circuit from ground to test terminal 41, to supply a busy test condition for the line to automatic switches, and at its middle and outer armatures and front contacts it closes the talking circuit from ground repeating coil 52, through the tip contact of plug 9 and jack 10 or 11, conductor 49, outer armature and front contact of relay 16, conductor 43, sub 5, conductor 42, middle armature and front contact oft relay 16, conductor 48, the ring contacts of plug 9 and jack 10 or 1 1, through supervisory relay 54 and repeating coil Winding 53 to battery.

In the two cases last assumed, we have traced calls originated at the manual line sub 3 and completed manually to automatic line sub 1 and manual line sub 5 respectively. If during the time when such connections are established an operator should plug into a multiple jack as 7 or 8 in the first case, and 10 or 11 in the second case, over the busy test condition, by the use of another cord circuit, in a weltknoivnmanner, it is obvious that such act would supply an additional multiple listening and talking connection to the lines sub 1 and sub 5 respectively.

' The details 'of the circuit of a calling manual line are shown in the drawings in connection With sub 5. W'hen the calling` manual line sub 5 is closed by the removal of the receiver, a circuit is closed from battery, left-hand Winding of relay 18, through theinner right-hand armature and back contact of relay 17, conductor 45, middle armature and back-contact of relay 16, conducincasso *and `back contact of relay 16, conductor 44,

fright-hand Vouter armature and back contact of relay 17, through the right-hand winding of relay 18 to ground. The operation of relay 18 closes acircuit from ground and answering lamp `ftobattery. Upon i receiving the signal from lamp 55 the op-` erator inserts her plug Athereby operating relay 16 in a well-known mannenwhiclirelay in turn breaks at its middle and outer armatures and back contacts, the operating circuit of relay 18, which in turn extinl5. i

f guishes lamp 55.

` From the above description it is obvious that all connections completed manually, are

1 accessible at all times "to the* switchboard operator, and that allcalls originated at an .automatic y subscribers l station are inaccessible to such operator at all times regardless.

of the character of the called partys line.

What is claimed is: a v 1 In a telephone system, a central office,

a telephone line terminating in said oflice, a

plurality of automatic switches having access to vsaid line, an operators switchboard atsaid office, a plurality of multiply cona nected jacks atsaid switchboard normally a disconnected from said line,` a plurality of' manually operable link circuits Vat said switchboard, and means Vincluding a relay "effective whenone of said switches is notconnected to said line to connect any one'of a said link circuits through any one of saidi jacks to said line.

2. ln a telephone system, a central office,

`V a line bank in said oiiice, a pluralitylof lines y terminating in said line bank, a plurality of 40 1 line bank, a plurality of multiply connected switches having access Ato said lines at said jacks associated with each of said lines at said office and normally disconnected from` `said lines, arelay individual to each of, said lines to connect.` said line to said multiply `connected jacks, and means for rendering said relay ineffective when said line is engaged by one of said automatic switches.

3. In a telephone system, avmanual switch- `board, a contact bank for automatic switches,

a line terminating in said contact bank, a

jack at said manual switchboard `associated `with said line, and a relay individual to said l line to said jack at said manual switchboard.` on its front contact, through .its armature lthereat normally disconected from saidfline,

automatic switches arranged to engage said terminals, a relay associated with said line for controlling the connection of said line to said jacks, means individual to said line for rendering said relay ineffective `when said terminals are engaged by one of said switches, a manually operable. link circuit,

vand means for rendering said relay effective to connect said line to said jacks when said link circuit is connected to one of said -j acks.

5. In a telephone system, a central exchange, a plurality of manual and auto inatic telephone lines extending to said exchange, a plurality of automatic link cir-` cuits for extending certain o'fsaid lines, a plurality of manually operable link circuits for extendingother lines, fmeans includinga relay for connecting any one of saidmanually operable link circuits to anyV one of said lines and a second relay operable to connect said certain lines to said a automatic link circuits and to render the first named relay ineffective. i

`6. ln a telephone system, telephone lines, meansfon interconnecting said lines, means including a multiple jack and a relay through contacts of which relay operators supervision is supplied to connections between said lines where the call originated at certain linesandlmeans including another re` lay madeoperative to extend another line and toprevent operators supervision to aV connection where the call originated at said other line.

In witness whereof, I hereunto subscribe a HENRY PjcLAnsEu `inyname this'28th day of December, A. D. i V191 

